Powertrain, shared range

P34B8 B Camshaft Position Actuator Temperature Sensor Circuit Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P34B8 is the circuit fault for the heat sensor inside exhaust camshaft actuator B of bank 2, the row without cylinder 1 on a V or flat engine. If P34B4 is stored at the same time, a shared feed, a common ground or the control module is more likely than two failed sensors at once. The code family presumes an electrically driven exhaust phaser with its own heat-sensitive driver: NTN-SNR files it under outlet camshaft adjustment, and Aisin's patent explains why such a driver carries a temperature sensor at all. A carmaker using P34B8 could not be found in bulletins or official service information. In practice: check plug and harness on bank 2 first, then the actuator itself. For a signal stuck low or high on bank 2 see P34BA and P34BB.

Likely causes

Connector or harness at the bank 2 exhaust actuator open
Shared supply or ground faulty (when bank 1 also reports)
Temperature sensor in the bank 2 actuator failed

Symptoms

  • Malfunction indicator lamp lit
  • Exhaust phasing on bank 2 restricted, banks may run slightly unevenly

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–850
Time0.5–3.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

cam actuator b temp sensor b2sensor wiring

Related codes

P34B4P34B9P34BAP34BBP34A8

References: law.cornell.edu, ntn-snr.com, patents.google.com.